When KoL players reach level 3 they are eligible to join a clan, which can provide various benefits, such as a daily meat stipend, extra daily adventures, and a gym to work out in for stat gains. (When a new clan is formed, the leader must buy each benefit separately.) Many clans also have an active message board and a collective stash of spare items. Some clans choose to engage in inter-clan warfare.

Some clans are made up of people who know each other outside of the game, while others are made up of people who meet each other through the in-game chat channels. A few clans accept all applicants.